Add GCP Batch scheduler docs (#670)

* add gcp batch docs

* add right path

* update docs

Author: priyaramani

docs/source/index.rst

@@ -77,6 +77,7 @@ Works With
    schedulers/ray
    schedulers/aws_batch
    schedulers/lsf
+   schedulers/gcp_batch
 
 .. fbcode::
 

docs/source/schedulers/gcp_batch.rst

@@ -0,0 +1,18 @@
+GCP Batch
+=================
+
+.. automodule:: torchx.schedulers.gcp_batch_scheduler
+
+.. currentmodule:: torchx.schedulers.gcp_batch_scheduler
+
+.. autoclass:: GCPBatchScheduler
+   :members:
+   :show-inheritance:
+
+.. autoclass:: GCPBatchJob
+   :members:
+
+Reference
+~~~~~~~~~~~~
+
+.. autofunction:: create_scheduler

torchx/schedulers/gcp_batch_scheduler.py

@@ -12,6 +12,12 @@
 
 This scheduler is in prototype stage and may change without notice.
 
+Prerequisites
+==============
+
+You need to have a GCP project configured to use Batch by enabling and setting it up.
+See https://cloud.google.com/batch/docs/get-started#prerequisites
+
 """
 
 from dataclasses import dataclass
@@ -104,8 +110,8 @@ class GCPBatchScheduler(Scheduler[GCPBatchOpts]):
 
         $ pip install torchx[gcp_batch]
         $ torchx run --scheduler gcp_batch utils.echo --msg hello
-        gcp_batch://torchx_user/1234
-        $ torchx status gcp_batch://torchx_user/1234
+        # This launches a job with app handle like gcp_batch://torchx/project:location:app_id1234 and prints it
+        $ torchx status gcp_batch://torchx/project:location:app_id1234
         ...
 
     Authentication is loaded from the environment using the gcloud credential handling.
@@ -120,9 +126,13 @@ class GCPBatchScheduler(Scheduler[GCPBatchOpts]):
     .. compatibility::
         type: scheduler
         features:
-            describe: |
-                Partial support. GCPBatchScheduler will return job status
-                but does not provide the complete original AppSpec.
+            cancel: true
+            logs: true
+            describe: true
+            distributed: true
+            workspaces: false
+            mounts: false
+            elasticity: false
 
     """